2,4-diamino-5-(3-alkoxy-4,5-methylene-dioxybenzyl)pyrimidine

ABSTRACT

1. A COMPOUND OF THE FORMULA   4-R,6-((R1-O)2-CH-CH(-CN)-)-1,3-BENZODIOXOLE   WHEREIN R IS LOWER ALKOXY AND R1 IS LOWER ALKYL OF 1-7 CARBON ATOMS.

United States Patent 3,850,962 2,4-DIAMINO-5-(3-ALKOXY-4,5-METHYLENE-DIOXYBENZYL)PYRIMIDINE Emanuel Grunberg, North Caldwell, and Max Holfer,Nutley, N.J., assignors to Hoffmann-La Roche Inc.,

Nutley, NJ.

N Drawing. Original application Dec. 1, 1971, Ser. No. 203,869, nowPatent No. 3,787,409. Divided and this application Oct. 10, 1973, Ser.No. 404,954

Int. Cl. C07d 13/10 US. Cl. 260-3405 1 Claim ABSTRACT OF THE DISCLOSURE2,4-Diamino-5-(3-alkoxy 4,5 methylenedioxybenzyl) pyrimidines, such as,for example 2,4-diamino-5-(3-methoxy 4,5methylenedioxybenzyl)pyrimidine, prepared from the correspondingbenzaldehydes, are described. The end products are useful aspotentiators of the antibacterial activity of sulfonamides, as well asantibiotics.

This is a division, of application Ser .No. 203,869, filed Dec. 1, 1971,now US. Pat. No. 3,787,409.

BRIEF SUMMARY OF THE INVENTION The invention relates to compoundscharacterized by the formula wherein R is a lower alkoxy,

and addition salts thereof with pharmaceutically acceptable acids. Thecompounds of formula I are useful as potentiators of the antibacterialactivity of sulfonamides, as well as antibiotics.

DETAILED DESCRIPTION OF THE INVENTION The invention relates to compoundscharacterized by the formula wherein R is lower alkoxy, which preferablyhas from 1 to 7 carbon atoms, for example, methoxy, ethoxy, propoxy,butoxy, pentoxy, and the like.

CHO CH;

CHzO R1 II alkali metal alkoxide RzOH III

OH2OR1 3,850,962 Patented Nov. 26, 1974 alkali metal alkoxide 1R2OH CN0- 0% /0 R1 t. s

lguanidine OHN O OH2C C--NHz wherein R is as previously described and Rand R are lower alkyl of 17 carbon atoms; methyl is preferred.

The foregoing reaction is carried out by first reacting an aldehyde offormula II with a fl-lower alkoxy propionitrile of formula III in thepresence of an alkali metal lower alkoxide, such as sodium .methoxide,potassium ethoxide, etc. and a lower alkanol of the formula R OH, e.g.,methanol, ethanol, propanol, etc. The reaction temperature is notcritical, but it is generally in the range of about 60 to about C. Thereaction product obtained is a compound of formula IV which is readilyconverted into a compound of formula V by treatment with R OH in thepresence of an alkali metal lower alkylate under substantially anhydrousconditions. The reaction temperature is also not critical for this step,and temperatures of about 60 to about 140 C. are suitable here also. Acompound of formula V is then reacted with guanidine, in the presence ofa solvent, if required, to give an almost quantitative yield of acompound of formula I.

The aldehydes of formula II are known compounds or can readily beprepared by known techniques, for example, by the Rosenmund method(Organic Synthesis, 1.0., p. 1332), or by the method of W. Bonthrone andJ. W. Cornforth, J. Chem. Soc. (c) 1202 (1969).

The compounds of formula I form acid addition salts and such salts arealso within the scope of this invention. Thus, the compounds of formulaI form pharmaceutically acceptable addition salts with, for example,both pharmaceutically acceptable organic and inorganic acids, such asacetic acid, succinic acid, formic acid, methanesulfonic acid,p-toluene-sulfonic acid, hydrochloric acid, nitric acid, phosphoricacid, sulfuric acid, lactic acid, and the like.

The compounds of formula I are useful in combination with one or moresulfa drugs, such as, for example,

N (3,4-dimethyl-5-isoxazolyl) -sulfanilamide,

S-methyl-3-sulfanilamido-isoxazole,

N 2,6-dimethoXy-4-pyrimidinyl) -sulfanilamide,

N -ethoxyacetyl-N (5 -methyl-3 -isoxazolyl) -sulfanilamide,

N -(4,5-dimethyl-3-isoxazolyl)-sulfanilamide,

N (5 ,6-dimethoxy-4-pyrimidinyl) -sulfanilamide,

and the like, as antibacterial agents. The addition of a compound offormula I to one of the above-mentioned sulfonamides results in a markedpotentiation of the antibacterial activity of the sulfonarnide. Thus,the compounds of formula I are useful as potentiators of sulfonamides.The combination of a compound of formula I and a sulfonamide is preparedsimply by admixture, which can ultimately be embodied into a suitableoral dosage form, as hereinafter described. Unexpectedly, the compoundsof formula I also potentiate the antibacterial activity of antibiotics,such as, for example, oxytetracycline, penicillin and the like. Thus,the compounds of formula I are also useful as potentiators ofantibiotics. The combination of a compound of formula I and anantibiotic is prepared simply by admixture, which can ultimately beembodied into a suitable oral dosage form, as hereinafter described.

The ratios in which a therapeutically active compound of formula I and asulfonamide are utilized can be varied within wide limits. For example,the combination can con tain from about 1 to about 50 parts, preferablyfrom about 1 to about 20 parts, of sulfonamide or an equivalent amountof salt thereof to one part of a compound of formula I or equivalentamount of salt thereof.

The ratios in which a therapeutically active compound of formula I andan antibiotic are utilized can be varied within wide limits. Forexample, the combination can contain from about 1 to about 50 parts,preferably from about 1 to about 20 parts, of antibiotic or anequivalent amount of salt thereof to one part of a compound of formula Ior equivalent amount of salt thereof.

The products of the invention can be incorporated into standardpharmaceutical dosage forms, for example, they are useful for oral orparenteral application with the usual pharmaceutical adjuvant material,for example, organic or inorganic inert carrier materials such as Water,gelatin, lactose, starch, magnesium stearate, talc, vegetable oils,gums, polyalkyleneglycols, and the like. The pharmaceutical preparationscan be employed in a solid form, for example, as tablets, troches,suppositories, capsules or in liquid form, for example, as solutions,suspensions or emulsions. The pharmaceutical adjuvant material can beadded and can include preservatives, stabilizers, wetting or emulsifyingagents, salts to change the osmotic pres sure or to act as buffers. Theycan also contain other therapeutically active materials. The combinationof a compound of formula I and a sulfonamide can be administered in unitdosage forms which contain 500 mg. of sulfonamide or an equivalentamount of a salt thereof and from about 10 mg. to about 100 mg. of acompound of formula I or an equivalent amount of a salt thereof.However, it is also within the scope of the invention to utilize a unitdosage form which will contain from about 250 mg. to about 750 mg. ofsulfonamide or equivalent amount of a salt thereof and from about 5 mg.to about 150 mg. of a compound of formula I or equivalent amount of asalt thereof.

The combination of a compound of formula I and an antibiotic can beadministered in dosage forms which contain 250 mg. of antibiotic or anequivalent amount of a salt thereof and from about 5 mg. to about 50 mg.of a compound of formula I or an equivalent amount of a salt thereof.However, it is also within the scope of the invention to utilize a unitdosage form which will contain from about 250 mg. to about 750 mg. ofantibiotic or equivalent amount of a salt thereof and from about 5 mg.to about 150 mg. of a compound of formula I or an equivalent amount ofsalt thereof.

The frequency with which any such unit dosage will be administered to awarm-blooded animal will vary, depending upon the quantity of medicamentpresent therein and the needs and requirements of the warm-bloodedanimal.

The sulfonamides hereinbefore described form salts with pharmaceuticallyacceptable bases, for example, they form salts with alkali metal bases,such as, for example, sodium hydroxide, potassium hydroxide or the like.

The following examples further illustrate the invention. All parts areby weight and all temperatures are in degrees centigrade, unlessotherwise mentioned.

4 EXAMPLE 1 Preparation of3-methoxy-4,5-methylenedioxy-amethoxymethylcinnamonitrile 3.8 g. ofsodium were dissolved in ml. of methanol under reflux. 56 g. ofmethoxypropionitrile and 60 g. of 3methoxy-4,S-methylenedioxybenzaldehyde were then added and refluxed inthe methanol mixture for 5 hours. Upon chilling,3-methoxy-4,5-methylenedioxy-u-methoxymethyl-cinnamonitrile crystallizedin needles of m.p. =115, in a yield of 68 g.=83 percent. A sample foranalysis was recrystallized from methanol, m.p. 1155-1165".

Analysis.-C H NO Calcd: C, 63.2; H, 5.26; N, 5.67. Found: C, 63.15; H,5.22; N, 5.62.

EXAMPLE 2 Preparation of2,4-diamino-5-(3-methoxy-4,5-methylenedioxybenzyl) pyrimidine 12.8 g. ofsodium were dissolved in 185 ml. of methanol, under stirring and reflux,68 g. of 3-methoxy-4,5- methylenedioxy 0c methoxymethylcinnamonitrilewere added and the mixture was refluxed for 48 hours. The reactantdissolved gradually, and the solution darkened. Thereafter, the reactionwas quenched with 500 ml. of water and neutralized with 2 0 ml. ofacetic acid, followed by extraction with three portions of benzene,i.e., 600 +50+50 ml. The benzene layer was dried over sodium sulfate andcleared by filtering it through a filter containing charcoal. Thesolvent was evaporated in vacuo and the residue removed by distillationat 184-198, 1.5 mm. Hg. The product was a viscous colorless oil of n=1.5320. 41 g. was refluxed with 290 ml. of 1 molar methanolic guanidinesolution for 1.5 hours. The methanol was then removed by distillationover an oil bath at and the residue kept at that temperature until itsolidified to a crystalline mass (10-15 min.). Thereafter, the productwas slurried with water and filtered by suction. Yield of the crudeproduct was 37 g. :92 percent, m.p. unsharp 215.

To purify the crude product it was slurried with 120 ml. of acetic acidand heated until it had dissolved. Upon cooling, the acetatecrystallized as white needles which were pressed off an a suction filterand dissolved in 250 ml. of hot water. The solution was charcoaled andthe 2,4- diamino-5-(3-methoxy 4,5 methylenedioxybenzyl)pyrimidineprecipitated with an excess of ammonia, m.p. =236237, yield 28.5 g.=70percent.

Analysis.C H N O Calcd: C, 56.9; H, 5.11; N, 20.45. Found: C, 56.67; H,5.27; N, 20.35.

EXAMPLE 3 Preparation of3-ethoxy-3,4-methylenedioxy-a-methoxymethylcinnamonitrile To a solutioncontaining 2.16 g. of sodium in 10 0 ml. methanol, there were added 32g. of fi-methoxypropionitrile and 36.5 g. of 3-ethoxy-4,5-methylenedioxybenzaldehyde. Thereafter, the mixture was refluxed for 6.5 hours. 300ml. of water were added and the3-ethoxy-3,4-methylenedioxy-a-methoxymethylcinnamonitrile was extractedwith methylenechloride. Upon evaporation of the solvent and vacuumdistillation, the3-ethoxy-3,4-methylenedioxya-methoxymethyl-cinnaminonitrile had a b.p.of 0.3 mm. Hg. and mp. 64-65.

Analysis.-C H NO Calcd: C, 64.36; H, 5.79; N, 5.36. Found: C, 64.57; H,5.83; N, 5.28.

EXAMPLE 4 Preparation of3-ethoxy-4,S-methylenedioxy-a-cyanodihydro-cinnamaldehyde dimethylacetalTo 6.6 g. sodium dissolved in 96 ml. of methanol, 37.5 g. of 3-ethoxy4,5 methylenedioxy-a-methoxymethylcinnamonitrile were added. Theresutling mixture was refluxed for 24 hours. The solution was pouredinto 400 ml. water and was extracted with methylenechloride. Uponevaporation of the solvent, the product, 3-ethoxy-4,5-methylenedioxy-a-cyanodihydrocinnamaldehyde dimethylacetal, was vacuumdistilled and had a b.p. of 191/ 0.4 mm. Hg., n =1.5340.

Analysis.C H NO Calcd: C, 61.41; H, 6.53; N, 4.78. Found: C, 62.23; H,6.17; N, 4.78.

EXAMPLE 5 Preparation of2,4-diamino-5-(3-ethoxy-4,5-methylenedioxybenzyl) pyrimidine 30.5 g. of3 ethoxy-4,5 methylenedioxy-a-cyanodihydrocinnamaldehyde dimethylacetalwere added to 200 ml. of freshly prepared 0.2 molar solution ofguanidine in methanol, and the solvent was gradually removed bydistillation over an oil bath at a temperature of 120140. The residuewas heated for 10 minutes to 140-160 and it completely solidified to acrystalline mass. For purification, the mass was dissolved in 100 ml.hot acetic acid and the product allowed to crystallize as an acetateupon chilling. The latter was filtered by suction, dissolved in 400 ml.of hot water and the solution alkalized with ammonia to precipitate 2,4diamino 5 (3 ethoxy-4,5-methylenedioxybenzyl)pyrimidine as whitecrystals of free base having a m.p, of 202.5203.5.

Analysis.C H N O CalCd: C, H, N, 19.44. Found: C, 58.51; H, 5.72; N,19.69.

The starting material 3 ethoxy 4,5 methylenedioxy benzaldehyde wasobtained by methylenation of 3-ethylbenzaldehyde was obtained bymethylenation of 3-ethoxy- 4,5-dihydroxybenzaldehyde essentially by themethod of W. Bonthrone and J. W. Cornforth, J. Chem. Soc (C) 1202 1969).

White crystals, m.p. of -61, b.p. of 103104/0.1 mm. Hg.

Analysis.--C H O Calcd: C, 61.85; H, 5.19. Found: C, 61.70; H, 5.18.

3 ethoxy 4,5 dihydroxybenzaldehyde was obtained from 3 ethoxy 4 hydroxy5 bromobenzaldehyde, P. Mariella and J. M. Bauer, J. Org. Chem. 23: 120(1958) in analogy to Bradley, Robinson and Schwarzenback, J. Chem. Soc.811 (1930), white crystals, from water. m.p. of 117118.

Analysis.C H O Calcd: C, 59.33; H, 5.33. Found: C, 59.65; H, 5.52.

EXAMPLE 6 Capsule formulation Per capsule, milligrams N-(3,4-dimethyl-5-isoxazolyl)-sulfanilamide 250 2,4 diamino 5(3-methoxy-4,S-methylenedioxy- Procedure (1) The N (3,4 dimethyl 5isoxazolyl)-sulfanilamide, 2,4 diamino 5 (3methoxy-4,5-methylenedioxybenzyl) pyrimidine, lactose and corn starchare mixed in a suitable mixer.

(2) The mixture is further blended by passing through a comminutingmachine with a No. 1A screen with knives forward.

(3) The blended powder is returned to the mixer, the tale added andblended thoroughly. The mixture is then filled into No. 4 hard shellgelatin capsules on a capsulating machine.

6 EXAMPLE 7 Capsule formulation Per capsule, milligrams Oxytetracycline250 2,4 Diamino 5 (3-methoxy-4,S-methylenedioxybenzyl)-pyrimidine 25Lactose 68 Corn starch 27 Talc 5 Total weight 375 Procedure Tabletformulation Per tablet, mg.

N (3 ,4-dimethyl-5-isoxazolyl sulfanilamide 225 2,4-Diamino-5-3-methoxy-4,S-methylenedioxybenzyl)pyrimidine 60 Lactose 233 Corn starchGelatin 12 Talc 15 Magnesium stearate 5 Procedure (1) 2,4-Diamino 5(3-methoxy-4,S-methylenedioxybenzyl)pyrimidine, N(3,4-dimethyl-5-isoxazolyl)sulfanilamide, corn starch and lactose arethoroughly mixed in suitable blending equipment and granulated with a 10percent gelatin solution.

(2) The moist mass is passed through a No. 12 screen, and the granulesare dried on paper-lined trays overnight.

(3) The dried granules are passed through a No. 14 screen and placed ina suitable mixer. The talc and magnesium stearate are added and blended.

(4) The granulation is compressed into tablets weighing approximately650 mg. each, using punches having an approximate diameter of 12.7 mm./z"). The final tablet thickness is about 5.35 mm.

EXAMPLE 9 Tablet formulation Per tablet, mg.

(1) 2,4-Diamino-5-(3-methoxy 4,5 methylenedioxybenzyl)pyrimidine,oxytetracycline, corn starch and lactose are thoroughly mixed insuitable blending equipment and granulated wtih a 10 percent gelatinsolution.

(2) The moist mass is passed through a No. 12 screen, and the granulesare dried on paper-lined trays overnight.

(3) The dried granules are passed through a No. 14 screen and placed ina suitable mixer. The talc and magnesium stearate are added and blended.

(4) The granulation is compressed into tablets weighing approximately650 mg. each, using punches having an approximate diameter of 12.7 mm./2"). The final tablet thickness is about 5.35 mm.

EXAMPLE 10 Suspension formulation Gm. per liter Methylparaben 0.9Propylparaben 0.5 Sodium edetate 0.1

2,4-Diamino-- 3 -methoxy-4,S-methylenedioxy- Lactic acid 85%: 8.3 cc?NaOH-40% Solution, q.s. to pH 5.1. Distilled water, q.s.: 1000 cc.

Procedure (1) The methyl and propyl parabens, sodium edetate and lacticacid are dissolved in 750 cc. of boiling distilled water. The2,4-diarnino-5-(3-methoxy 4,5 methylenedioxybenzyl) pyrimidine is addedwith stirring.

(2) The complex magnesium aluminum silicate is then added and cooked for1 hour in a water bath at 80-85 C.

(3) The sodium benzoate is dissolved in 30 cc. of water and added to themixture. The sucrose and sorbitol solution U.S.P. are then added.

(4) The tragacanth is added to the glycerin with high shear and thenadded to the mixture with high mix.

(5) The methyl cellulose is dissolved in 525 cc. of water, heated to60-65 C. and mixed for -15 minutes. The sorbitan monolaurate isdissolved in cc. of heated water and added to the methyl cellulosesolution. N -(3,4-dimethyl-5-isoxazolyl) sulfanilamide is added withhigh shear-when this is uniform, it is added to the mixture.

(6) The colors and flavors are added when needed.

(7) The pH is brought to 5.1 with 40 percent NaOH and the mixturebrought to volume.

(8) The mixture stands overnight before versating and homogenizing.

EXAMPLE 11 The unexpectedly increased antibacterial activity ofantibiotics and, for example, N-(3,4-dimethyl-5-isoxazolyl)sulfanilamide, when combined with2,4-diamino-5-(3- methoXy-4,5-methylenedioxybenzyl)pyrimidine in thetreatment of various bacterial infections was demonstrated utilizing theprocedure set forth hereinbelow.

Swiss albino mice weighing 18 to 20 grams were in fectedintraperitoneally with 100 to 1000 minimal lethal doses of the organism.The inoculum was obtained from a properly diluted overnight brothculture. In all infections except D. pneumoniae, S. pyogenes and K.pneumoniae, the inoculum was finally diluted in 5 percent hog gastricmucin.

For all infections, the test animals were treated orally by gavage with1.0 ml. of the desired concentration of the single drug or theappropriate sulfonamide-pyrimidine combination in 1 percentcarboxymethylcellulose. Treatment consisted of a total of 6 doses. Twotreatments, five hours apart, were administered on the day of and the.day following infection and one treatment on the second and third daysfollowing infection. The first dose was administered 510 minutes afterinfection. When combinations were administered, varying concentrationsof sulfonamide or antibiotic were prepared in the presence of aninactive concentration of a potentiator of the invention. Theexperimental observation period was 14 days. Heart blood from micesuccumbing during this period of time was cultured on appropriate solidmedia to determine the presence or absence of the infecting organism.

Results obtained are given in Tables I and II.

TABLE I The antibacterial effect of N-(3,4-dimethyl-5-lsoxazolyl)sulfanilamide in combination with, e.g.,2,4-diamino-5-(3-methoxy-4,5-methylenedicxyllgelnzybpyrimidine againstbacterial infections in mice is set forth Dose: mgJkg. Increasedactivity a 2,4-diamino 5 (3- of N -(3,4-dimethoxy-4,5-methyl-5-isoxazole) methylenedioxysulfanilamide benzyl) (x-fold Organismpyrimidine potentiation) D. pneumoniae No. 6301 50 11. 9 25 11 10 2. 3

S. pyogenes ..r 50 31.3 25 3. 9 10 1. 4

S. aur us Smith 5 2. 1 E. coli 257 10 5. 7 A. pneumonzae A 5 2. 3 P.vulgaris 10 9. 1 5 2. 9

S. typhosa P. 58a 5 2. 5

Dose sulfonamide alone 3 Increased activity (xi-01d) Dose sulfonamide incombination These doses of2,4-diamino-5-(Ii-methoxy-4,5-methylenedioxybenzyl)- pyrimidine whenadministered alone are inactive.

TABLE II The antibacterial effect of Penicillin or Oxytetracycline H01in combination with 2,4-diarnino-5(3-methoxy-4,5-Inethylened.i0xybenzyl) -pyrim idine against bacterialinfections in mice is set forth below b These doses of2,4-diamino-5-(3-methoxy-4,5-methylenedioxybenzyl)- pyrimidine whenadministered alone are inactive.

What is claimed is: 1. A compound of the formula R ON Q- (LHz( s whereinR is lower alkoxy and R is lower alkyl of 1-7 carbon atoms.

References Cited UNITED STATES PATENTS 3,395,176 7/1968 Sletzinger eta1. 260340.5

J. H. TURNIPSEED. Assistant Examiner DONALD G. DAUS, Primary ExaminerUS. Cl. X.R. 260-2564 N

1. A COMPOUND OF THE FORMULA